Underreamer for hydraulic rotary well drilling



Nov 3 i925.

` 1,559,761 L. E. NEBERGALL.

UNDERREAMER FOR HYDRAULIC ROTARY WELL vDRILLING IH I r '1`\\ ai Q".filr'l 55,25

Filed Nov. 5, 1923 @mue/Moz Patented Nov. 3, 1925.

UNITED STATES PATENT OFFICE.

LORAN E. NBERGALL, OF DENVER, COLORADO.

UNDEBREAMER FOR HYDRAULIC ROTARY WELL` DRILLIN'G.

Application led November 3, 1923. Serial No'. 672,601.-

particularly to devices for use in connection with hydraulic rotarydrilling mechanism. It is the object of my invention to provide asimple, durable, ctlicient and relatively inexpensive under-reamingtool, adapted for use in series with other hydraulic rotaryA drillingtools, and'to operate beneath\ the lower end ofthe well-easing; forenlarging y the hole formed by the usual bit or drill,

whereby the casing may readily enter the enlarged portion of the hole.vA further object of my invention is to provide a hydraulic rotaryundcr-reamer with which the cuttings 0r material loosened thereby willbe in a finely divided condition, so as to be freely carried out of thehole b y the upward current of slush therein, and vnot ball `or clog theslush-return passages. Further objects of my invention are to provide anunder-reamer adapted to pass freely through the well-casing during theinsertion and withdrawal of the string of drilling tools,.to providemeans by which the cutting blades of the reamer are automaticallyexpanded by the hydraulic pressure from the slush-pumps when thedrilling operations are started, and to provide means by which saidblades are-'automatically forced inwardly to a retracted or foldedposition as the tool is raised from its operating position intothewell-casing.

In the accompanying drawings Fig. 1 is a longtiudinal or verticalsection of an under-reamer embodying my invention, and showing portionsof the devices associated therewith when it is in use, Fig. 2 is a sideelevation of the same, and4 Figs.. 3, 4 and 5 are detail horizontal ortransverse sections, taken, respectively, on the lines 3 3, 4-4 and 5.-5of Fig. 1.

In carrying out my invention I provide a tubular stem (S of which thelongitudinal or axial opening 7 comprises the Waterchannel forconducting water or slush through thereamer to thebit or drill con--nected below the` same. lAt each .end'of same figure.

said tubular stem there is a tapered threaded portion 8, 'similar to thepin-end of the usual tool-joints employed for connecting hydraulicdrilling tools and stands of drillpipe. Adjacent to the threaded endportions 8 .are the cylindre-segmental neck-portions 9 and 10, havingflat opposite sides as shown in Figs. 4 and 5. Adjacent to saidneck-portions 9 and 10 the stemis shoulderedoutwardly to the diameter ofthe main body-portion, which is slightly conical or tapering from end toend, being f smaller at the lower than at the upper end. In the outerpart of the tapering body-portion, at opposite sides thereof, arelongitudinal grooves or channels in which are disposed the folding wingsor blades 11. The wing-grooves or channels are of uniform depththroughout their length, thus being divergent from their lower to theirupperk ends, or parallel respectively with diametrif cally oppositesides of the stem-body. The j deepest portion of each groove issemi-cylindrical in sectional form, and the inner portions of the wingsor blades lit pivotally therein so that they may swing in and out aboutlongitudinal axes, from extended positions at which their outer edgesproject beyond the stem-body as shown :in Fig. 3; to

retracted or folded positions at which the'y blades lie vWholly Withinthe stem-body' periphery as indicated by dotted lines in the Formedintegrally with the upper and lower ends of the blades, adjacent to theneck-portions 9 and 10, are the pivot-pins 12 which fit rotatably in thepivot-plates 13 and 14. Said pivot-platesare of diameters the same asthe respectively adjacent ends of the stem-body, and the thickness ofsaid plates is the sameas the length of the neck-portions, the centralopenings of the` plates being of the same -cylindro-segmental form assaid neck-por-v tions, whereby to tit slidably but non-rotativelythereon. The pivot-plates are retained in place upon the neck-portionsof the stem by means of the caps or end-members 15 and 16, which areinternally threaded to screw'upon the pin-ends 8 of the stein. Each ofsaid end-members or caps has a central passage or Water-channelextending throu`V h the same and communicating with the channel 7through the stem 6. At the ends adjoining the pivot-plates the eaps'areof the same diameter Ias the respective Y, plates, and from said endsthey are conically tapered toward the opposite ends. -In the illustratedstructure the upper cap l5 is internally threaded at its upper end' torec'ei the lower en d of' the dri l-pipe 17 and t lower end of thelower-cap 16 has an internal thread or box adapted to receive the pin 18of a drill or other tool to be operated below-the under-reamer.

In the operation of the under-reamer the same is rotated in thedirectionindicated in Fig. 3, and itwill be seen that the winggroovesare so Shaped that when the blades are in extended position they will besupported at their rearward sides, while their inner semi-cylindricaledges are retained within the corresponding sockets or bottom` portionsof the wing-grooves, whereblydto a es effectively resist any tendencyfor the b to be twisted out of the grooves or to cause excessive..stresses upon the pivotpins 12. In the retracted 0r folded positions ofthe blades, their ilat front -faces rest against the iiat tangentialfaces 19 of the grooves in the stem. On the outer edges of the blades,at the u per portions thereof, are beveled or incline portions 20, 'asshown, so that when the reamer is withdrawn or raised from its operatingosition 'and enters the lower end of the wel casing 21, the latter willengage Said inclined ed es 2() and cause the blades to .swing to the fod.

ed positions' within the grooves. A plurality of holes or passa es 22extend from the central water-charme 7 of the stem outwardly to thetangential faces 19 ofl the grooves. In the operation'of the reamer,

after the sanne' has been lowered through the casing 21 with the bladesin the folded sition, a part of the water or slush, which 'tudmalgrooves, and means at the' ends of thus automatically causing the4opening of4 the blades tothe extended or operating po'-l 'sition whenthe slush-pumps are started at the `beginning of the drilling operation.The water or slush discharged throu h the passages 22 keeps the cuttingscleare from the blades during the operation, and the space kept open'about the reamer-stem, by the cutting actioii of the blades, affords anample passage for the upward or return flow of slush from the drill orbit operating below the reamer. By reason of the. outward inclination ordivergence of the blades, all portions of their rectilinear cuttingedges are similarly utilized, and wear thereof is kept at a minimum. Thereamer is so proportioned that at the lower end the blades will 'enterthe holeformed by the drill. or bit, while the reamed hole completed bythe upper portions of the/blades will be of such size that theWell-casing 21 may 'freely enter the same, the enlargement of thedrilled hole being from a diameter less than the inside tions and t 'theblades being diameter of the casingto a diameter slightly.

up lby the current of .slush passing upward about the e reamer from thedril y plemented by the iluid emerging from the passages 22.

N ow, having defnribed my, invention, what I. claim and ent is :v I `1.A hydraulic rotary under-reamer, comprising a tapering tubular stemhaving -lon'- gitudinal grooves in the outer portion thereof, saidgrooves being substantially parallel with4 the Iadjacent taperingsurfaces of the f stem, cutting blades mounted insaid grooves and swingale inwardly and outwardly between folded positiens Wholly within saidgrooves and extended positions at which the longitudinal edges oftheblades erally frein the stem, said bla es having inclined edges atthe upper portions thereof adapted for engagement with the vwell-easingto swing the blades tov their folded posie .longitudinal cutting ed esof parallel with 'the ladjacent tapering "surfaceso the stem, therebeing lateral assages extendingkfrom the central lon itu nal asse e ofthe tubular stem to ischarge uid t erefromv into the longisaid 'tubularvstem for connecting the same withdthe; other tools off a series.

g tools below, sup-- desire-to secure by Letters Pat-.

2. A hydraulic rotary under-remuer, com-' Erlsing a tubular `stemvhaving a ta ered y-portion and provided with long1tudi" nal grooves inthe outer ypart thereof and lateral passagesy extendin from-the centrallongitu inal passage, cutter blades disposed in-said grooves and movablepivotally' therein about lon tudinal axes, whereby to extend laterallyom the sides of the body orto fold pivot-pins at the ends of saidblades, pivotlates'at the ends of said taperedfstembody or engaging saidpivot-pins, means for se curing said pivot-p ates upon the stem-body,and tubular members at the ends of the stembody tools of a series.

3. In a hydraulic rotary wellv drilling to said grooves into saidgrooves,

for connecting the same with other mechanism, an under-reamer comprisinga` tubular stem, means at the ends of said stem for connecting the samein series with other tools, the outer portion of said stem beinglongitudinally grooved and there being passages connecting said grooveswith the central boreof the stem, and cutter blades disposedin saidgrooves and movable pivotally about axes extending logitudinaliythereof, said blades having portions engageable b3' the well-casing toswing the blades into the grooves, the passages from the central bore ofthe stem being adapted to dir ,iz fluid therefron'i against the bladesin tie grooves, whereby to swing the saune outwardly, the siem beingtapered .from the' upper to the lower end thereof, and the pivotal axesand outer Cutting edges of the blades being so inclined to the axis ofthe stem that the ,blades project uniformly beyond. the tapering outersurface of the stem.

L E., NEBERGALL.

